Pietersen batted for over three hours and faced 141 balls with four fours.

Flintoff, playing his first Test of the season after missing the home series win over the West Indies with a knee injury, struck a couple of booming drives to the delight of fans hoping he could repeat his Ashes heroics of 2005.

Meanwhile Prior, whose fifty came in just 54 balls, square-drove Siddle for four with one of the shots of the day.

The bowlers were though given a boost by Mike Hussey.

Left-hander Alastair Cook (10), playing loosely away from his body against Hilfenhaus, saw Hussey hold a brilliant diving one-handed chance in the gully.

Ravi Bopara, hit second ball in the throat by the lively Siddle and and on the head by a Mitchell Johnson bouncer, struggled.

By contrast, England captain Andrew Strauss, looked secure while making 30. Yet it was the left-hander, not Bopara, who gloved a well-directed Johnson bouncer to Clarke in the slips.

And Bopara's innings of 35, which followed a run of three hundreds in as many Tests, ended when he spooned a catch off Johnson to Phillip Hughes at point.

Kevin Pietersen, who made 69, gave his wicket away to leave England 241 for five.

Pietersen had batted in largely responsible fashion until he rashly tried to sweep spinner Nathan Hauritz's fifth ball back from well outside off-stump and top-edged a gentle catch to Simon Katich at short leg.

"I think if you look at the first day of previous Ashes series, we would take 336 for seven - definitely," said Pietersen. "Being greedy, you would maybe say 'five down'. But with a wicket that is turning off the straight, I will take that."

Reflecting on his own dismissal, Pietersen said: "I swept the ball on to my helmet. If it hadn't hit my helmet I might have got away with it."

Australia coach Tim Nielsen mentioned: "I thought it was a pretty even day until a couple of late wickets got us back into the game," he said.

"Peter (Siddle) getting those two late wickets gives us some momentum going into tomorrow," he added.

Peter Siddle was rewarded for his perseverance with two late wickets as he helped Ashes holders Australia regain momentum at the end of a see-saw opening day in the first Test against England.

England were 336 for seven at stumps here at Sophia Gardens on Wednesday after Siddle - like all the members of holders Australia's attack making his Ashes debut - had removed Andrew Flintoff for 37 and Matt Prior for 56.

Flintoff played on after flat-footedly trying to cut. It was a poor stroke but the wicket was no more than fast bowler Siddle deserved and saw the end of a partnership of 86 which had taken just 95 balls to compile.

Prior, making his Ashes debut, was then bowled by a fine inswinging delivery from Siddle in the penultimate over of the day to leave the quick with figures of two wickets for 93 runs from his 23 overs.

South Africa-born Pietersen and Collingwood, who'd joined forces when England were 90 for three, batted through the second session and went 21 overs between boundaries.

When fast bowler Brett Lee, a veteran of 76 Tests, was ruled out on Monday with a rib injury it meant Australia, who thrashed England 5-0 in 2006/07, would go into this match with no Ashes experience in their attack.